//
// Created by DP on 2025/9/16.
//
#include <algorithm>
#include <iostream>
#include <map>
#include <queue>
#include <sstream>
#include <stack>
#include <vector>
#include <set>
#include <unordered_set>
using namespace std;
#define ll long long


// 双向链表
//https://codefun2000.com/p/P2393

//并查集
// https://codefun2000.com/p/P3294
//https://codefun2000.com/p/P2334
//https://codefun2000.com/p/P2276

//二叉搜索树
//https://codefun2000.com/p/P2327
//https://codefun2000.com/p/P2273

//排序
// https://codefun2000.com/p/P2848
//https://codefun2000.com/p/P2261
//https://codefun2000.com/p/P2375

// 中等
//https://codefun2000.com/p/P3553
//https://codefun2000.com/p/P2333
// https://codefun2000.com/p/P2315

//树状树组
//https://codefun2000.com/p/P2933
//https://codefun2000.com/p/P2808


